Break-downs and repairs of critical machinery in an oilfield and other seal-requiring operations process can result in inefficient operation, loss of operating time, increased operating expenses, and potentially loss of revenue. Even scheduled, routine maintenance of machinery, including replacement of worn components, results loss of time and increased operating expenses. For example, rotary seals used to seal around drive shafts in top drive drilling systems or casing systems, may become worn and may require replacement during the life of the top drive. In conventional systems, accessing and removing seals can be a time-consuming process and in some instances, may require substantial disassembly of the top drive or associated equipment. This results in the downtime and inefficiencies discussed above. For example, it may take up to about 15 hours to replace a rotary seal in a lower housing associated with a top drive because it may be necessary to first remove other components of the top drive, such as a pipe handler and a gear case, for example.